Hayley and Jonathan Hunt, who have run North Parade Fisheries for 23 years at 1 North Parade, have evidence that it was the home of a fried fish dealer in 1908.
The couple have entered the shop in a National Federation of Fish Fryers search to find the oldest fish and chip shop in the UK.
The federation's search was launched after a fish shop called 'The Oldest Fish and Chip Shop in the World' in Yeadon - which originally opened in 1865 - stopped trading.
Local historian Alex Cockshott and customers helped the couple trace the shop's history.
The 1909 Robinson's Directory of businesses lists 1 North Parade in Ilkley as the home of fried fish dealer J W Pollard.
And a 1908 Kelly’s Directory also lists 1 North Parade as the home of J W Pollard, fried fish dealer.
The Hunts found out from West Yorkshire Archive Service that the property was built in 1904 by Tom and Isaac Dean and was first bought by grocer James Pollard.
Hayley said the couple originally thought J W Pollard bought the shop in 1904 and ran it as a grocers until 1908 when he changed it into a fish and chip shop.
But she said it is also detailed in the 1909 Robinson's Directory that J W Pollard had a grocers nearby at the junction of Wellington Road and Little Lane.
The couple don't believe he would have had two grocery shops so close together and reckon Mr Pollard opened the shop as a fish and chip shop in 1904, which would make it 116-years-old.
In 1933 the shop was bought by Norman Earnshaw, a fish restaurant proprietor.
Mum-of-two Hayley said Mr Earnshaw’s grandaughter remembers the coal fired frying range and going to the rail station with a wooden cart to get the fish from the train.
Hayley, whis is originally from Armley, said: "We feel like we are part of the community. The people that come in are more like friends than customers.
"It would be fantastic (to be named the oldest fish and chip shop in the UK.) There is a lot of heritage and history in the shop."
Earlier this month the YEP featured a Leeds fish and chip shop which has been owned by one family for 49 years and is at least 109-years-old.
The Village Fish Shop in Shadwell, is listed in the 1911 census as the home of 'fried fish dealer Henry Stead.'
Owner Mark Savage, 54, said he is still on the lookout for evidence to find out if fish and chips were served from the historic building before then
Mark, has also entered his shop in the National Federation of Fish Fryers search to find the oldest fish and chip shop in the UK.